US2613145A

US2613145A - crawford

Info

Publication number: US2613145A
Authority: US
Publication date: 1952-10-07
Anticipated expiration: 1969-10-07

Description

- OCt. 7, 1952 C, CRAWFORD y 2,613,145

APPARATUS FOR PRODUCING SYNTHESIS GAS lFiled Deo. 30, 1948 I N V EN TOR.

C/afafzre Z. Pan/f/a/d.

P t t d 1 aene Oct 7 952 if (STATES PATENT' OFFICE y y. ..rirrrlmurus''Foarecocente:SYNTHESIS 'GAS'.

Clarence L. .'Crawford; Plum'. Township, Allegheny' ration of. Delaware 'Thisflinvention relatestofan'apparatusiorcan rying out reactions at advanced temperatures-Jano superatmospheric pressures. More particularly "the :invention: relatesto :an apparatus; iorifproor; conversionzone. ir ..vvliich3a;k High-temperature 1.01am. (crue-#196).

.reactlonis carriedout,to ac'oolingfzone.4 More.- 'orenz the; apparatus -comprsesfa compact and .efcient; arrangement: of; the,- fseveral elements required tu operate @,procjess of :generating syn;-

educingr-aatgasf.comprising.hydrogen; andrcarbon 5 thesis: gas., monox'dali.. 1..' aesyntnesisiaas byfpartiallylreact.- The. apparatusr of the? invention includes an -ing .hydrocarbon-smith., oxygen :atteler/.lated .temelongated conversion tube. having heat retentive zperatures mdfsuneratmosphericpressures, Wallsfandagasrquench coolercomprising a plu- .A process-'Finn' the production of. Fischer;- rality :oiznarrow .heatexchangetubes terminating Tropsch;synthesisgasncomprisesa introducing :a l0 in. .upper zandlower tube sheets, thetubesibeing :mixturezofztnatural gasfzand zoxygen. intonaA con;- disposed? in v.parallel arrangement' and'fsurrounded version; `zone; which .:c'onifersion temperatures by- .a chamber. fora luidrheat exchange medium', .of `tlie:order: of; :1800?"120 28.69 Ei and.' pressures allA containedifin. a 'single pressure-tight vessel. zoitlreforderruf lO.rtcolipoundslpersquareinch The gas quench cooler is .positioned aroundl the .acemantaineds The composition. of; t'lievclnarge l5 conversiomtube. Conduits.arefprovidedleading .mixtureris sucligeas. toyproduceuponconversion from ythe conversion tube to. the gas quench -fapminture-xof conversion products, comprising 0001er.k `Conversion .gaSeSflleSSin One? direction desirable proportions of: carbon. monoxide and threiieh the `Conversion tube', through. the C011- .fnydroeen randrtofevolve. sufficient heat. tomainduits'and-:in the otherl direction. throughzther heat .tain-r the conversionitube:v at `the.:coni/ters',lon tem- 20 eehallgef tubes; peyamweg y Tlienyention will' be. .understood by :reference The conversion Vproducts; :initially formed are to theaecompanrne drawing, hereby mada-a ,notin.thermodynamic:equilibriumat-theconver- DelOf 'this Speeee'om IWheh Figure' 1r vS'feL .sionv temperature and.. therefore.V the; conversion Vertice-1 SeetOnalveW of ian apparatus embdying zone.f.shouldf-be:.:sufciently long `toprovi'de.an 25 the.rinvention.ald Figure. 2i`S aCI-OSS-Setienal equilibrium'zonewhereintheproducts arefmaixn View takenelOng'the lines A-A 0f Figure 1. tainedatan elevated equilibrium temperature The" apparatus 'dSClOSed-n the drawing conn .above 170e" fr'. untiithermoeynamic equilibrium siste of. apreSsure-'teht vessel- 'fc'ontainine an is substantiallyestablished. The;A equilibrium elongated open 'conversion tube 6, :and a quench compositionfat this temperature lis the --desired 30 cooler ATwloicb surroundsthe ycorwersion tube 6. composition. .Howeven `since thef eriuilibrium The. vessel 51 is of steel,is.partially.insulatedwith `composition varies-withltemperatura the actual bottom insulating bricks Svand top 'insulating composition uiouldchaneetowardfa.new equilib.- `bricks 9, andv containsan outlet Ifi leading from ium composition atsa-.newtemperature ifallowed tbe top ofthevessel. The conversion tube .'6 is .sufficient-.time To stabilize the desired compo,- 35 centered within vessel 5 and is formed of a steel .sitionandlobtain syntbesisgas-.under conditions cylinder lf2 containing heatlretentive insulating desirable.iur,.introductioninto `a synthesisl conbri'cks `if3',.;forming anannular heat retentive Wall vertersystemfftheinixtureattheconversionitemf le', and bottonrinsulating bricks i8. The con- .perature smmdfbeimmedatei-y and-substantially version tube isprovidec with radiaiiniets in the ,instantaneously cooled orquencheclto a substan.- 4G 'form .ofi-Ong nozzles .m .at the top thereof which tially unreactive temperature, preferably 'a tem,- extend Without vessel 5. The nozzles i6 are fed peraturel of .below..1300 byfan upper oxygen manifold I l" Vand Aa lowerA nat* (meer theimportant. problems inyolvedin `ural"'gaszrnanifold t8. These manifolds are suppracticinga process othisftype is tliatof-avoidplied by the valvedflines shown on `-Figure 2. ing any substantial lOSsobeat from the conn 45 Commits` lewhichlea'd from the interior of the version Zone or products prior to the time the con-versiontube to an annularspa'oe orl chamber products are subjected to substantially instanta- 121i are formed-.byarranging heat'retentvel-bricks neous cooling. It is essential thattbe cooling I3 to form apertures in the bottom of wall. I4 device employed be closely adjacent to. the exit below the bottom of' steel cylinder I2.. The of the conversion tube to avoid heat losses in 50 chamber 22.!v is formed-by tlfx'eflowerl portion of transferring the products from the tube to the zrefractory Wall. I'll,."the.^\vaterfWall 22,` 'bottom cooling device since slow loss of heat prior to `insulating 'bricks'. 3,'andt'thei lower tube sbeet'Zi; the: rapid cooling would produce undesirable fof quench.l cooler. 1.V The quench cooler is vchanges.;inA gas composition., This problem prearranged as an annulus around'ithe cylinderv I2 sentsa. .material difficulties` 1in; .preventing heat 55 Vand Aconsists l.of :a pluralitywofz'narrow steel gas transfenzparticularly transferrbyfradiation:from 'cooling` tubes. i241. positionedl in `parallel arrange- .onel zoneito. the other.. ment `'between the.- :lower- "tube sheet 23 and. an "The, apparatus, of thepresent'- inventionfproupperitube lsheet 26; A chamber .2:1 adapted to vdeseneective solution. ofizthe' problem vo prec'ontainl'a coolingj-mediium. such Sas Water "sur- Ventingltne transfer, .oft heat from the 'reaction 60 roundine'thevtubes'2f4ris formed by thei=upperand 3 wall 28 of vessel 5. The cooling medium is introduced through inlet 29 and withdrawn through outlet 3|.

The operation of the apparatus will be described in connection with a process for the production of synthesis gas. A mixture of natural gas and oxygen at an elevated temperature of about 1000 F. and a pressure of about 300 pounds per square inch is formed in nozzles I6 and introduced into conversion tube 6. The conversion tube is maintained at a temperature of about 2500 F. and a pressure of about 300 pounds per square inch, this temperature being obtained by the coni version of previous increments of the natural gas and oxygen mixture. The entering mixture is raised rapidly to its conversion temperature and is converted to conversion products comprising carbon monoxide, hydrogen, carbon dioxide and steam. These conversion products move downwardly in conversion tube 6 at a rate such that on reaching the bottom of the tube, they are of substantially equilibrium composition at the conversion temperature of 2500 F. The reactions occurring in conversion tube E produce a considerable amount of heat, loss of which is prevented in the apparatus described by the heat retentive wall i4 and bottom insulating bricks 8.

In order to cool or quench this equilibrium mixture substantially instantaneously, the conversion products are passed through conduits I9 into annular chamber 2l and without substantial reduction of temperature are introduced into the bottom of gas cooling tubes 24 where they are quickly cooled so as to pass from the heat exchange tubes at a temperature of about 900 F. The pressure of the exit gases will be substantially the pressure in the conversion tube i. e. about 300 pounds per square inch.

The apparatus disclosed is effective to prevent any premature cooling of the conversion products because the loss of heat by radiation to the quench cooler is substantially completely avoided. Thus, the only conversion gases which are in a position to radiate heat to the quench cooler are the gases contained in chamber 2| and these gases almost immediately pass into the heat exchange tubes. There is substantially no reduction of temperature of the conversion gases until they enter the gas cooling tubes 24.

Due to the structure of the quench cooler, and particularly the fact that the hot gases pass through the parallel gas cooling tubes 24 which are in contact with water acting as a cooling medium, substantially instantaneous cooling is accomplished which is effective to stabilize and iix the composition of the conversion products at the composition attained at the elevated conversion temperature of 2500 F.

The cooling medium employed is preferably water which, depending upon the plant requirements, is converted into high or low pressure steam.

It will be seen that the apparatus disclosed has the important advantage in addition to that of permitting a substantially instantaneous quench cooling of the conversion products of providing means for protecting the conversion zone from excessive cooling.

It will be recognized by those skilled in the art that the apparatus disclosed in the drawing can be modified in many ways within the scope of the invention. For example, the position of entering and exit conduits may be the reverse of that shown; i. e. the unit may be in effect inverted. In such case, the flow of gases through the conversion tube and the quench cooler will be in the opposite direction from that described. 'While it is important when carrying out extremely hightemperature reactions and using water as the cooling medium that the hot gases flow upwardly through the quench cooler, satisfactory results are obtained when carrying out lower-temperature reactions, particularly when using a different cooling medium, by causing the hot gases to flow downwardly through the quench cooler.

Obviously many modifications and variations of the invention as hereinabove set forth may be made without departing from the spirit and scope thereof and therefore only such limitations should be imposed as are indicated in the appended claim.`

I claim:

An apparatus for producing synthesis gas by conversion of hydrocarbons which comprises in combination in a pressure-tight vessel, an elongated conversion tube centrally and axially 1ocated in said vessel, closed at its upper and lower ends and insulated over substantially all of its inner surface by insulating heat retentive walls, said elongated conversion tube containing at least one inlet conduit at the top thereof extending from without the said vessel and a plurality of slots disposed in the bottom of and extending through the side wall of said conversion tube, cooling means comprising a lower tube sheet, a water wall beneath saidlower tube sheet and surrounded by the lower portion of said pressuretight vessel, vertical heat exchange tubes open at each end, an upper tube sheet, and a heat exchange chamber, said cooling means surround'- ing said conversion tube within said reaction vessel with its said lower tube sheet positioned at a higher vertical point 'than but immediately adjacent to said slots, and an annular chamber surrounding said conversion tube'closed at the lower end by an insulating heat retentive wall and bounded also by the insulating heat retentive side wall of the lower end of said conversion tube containing said slots, by said water wall, and by said lower tube sheet, said annular chamber being in communication with the interior of said conversion tube by means of said slots and with said heat exchange tubes, whereby hot reaction gases formed in said conversion tube flow downwardly through said conversion tube while they are maintained at an elevated equilibrium temperature by said insulating heat retentive walls of said conversion tube and pass from said conversion tube through said slots to said annular chamber while avoiding any substantial transfer of heat by radiation from said conversion tube to said cooling means and then flow upwardly through said cooling means.

CLARENCE L. CRAWFORD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS